Semiconductor device fabrication method using an interface control layer to improve a metal interconnection layer

ABSTRACT

A method for fabricating a semiconductor device having an aluminum (Al) interconnection layer with excellent surface morphology forms an interface control layer having a plurality of atomic layers before forming the Al interconnection layer. In the fabrication method, an interlayer dielectric (ILD) film having a contact hole which exposes a conductive region of the semiconductor substrate is formed on a semiconductor substrate, and an interface control layer having a plurality of atomic layers continuously deposited is formed on the inner wall of the contact hole and the upper surface of the interlayer dielectric film, to a thickness on the order of several angstroms to several tens of angstroms. Then, chemical vapor deposition (CVD) completes an Al blanket deposition on the resultant structure, including the interface control layer, to form a contact plug in the contact hole and an interconnection layer on the interlayer dielectric film.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a method for fabricating asemiconductor device, and more particularly, to a method for fabricatinga semiconductor device having a metal interconnection layer connected toa lower conductive layer via a fine contact.

[0003] 2. Description of the Related Art

[0004] Higher levels of integration in semiconductor devices have leadto contact holes having smaller diameters and higher aspect ratios.Accordingly, technologies that can effectively fill such fine contactholes have been suggested. A conventional physical vapor deposition(PVD) produces a layer having poor step coverage and thus does notcompletely fill a fine contact hole. As an alternative, chemical vapordeposition (CVD) can fill a contact hole with tungsten (W), forming atungsten plug. However, tungsten plugs have high resistivity andincrease contact resistance. Contact resistance increases further when atungsten plug reacts with an aluminum (Al) interconnection layer formedthereon. Blanket deposition of aluminum provides a relatively lowresistivity material that does not react with aluminum interconnectlayers. However, as the thickness of a CVD deposited Al layer increases,the surface morphology of the Al layer becomes more irregular whichmakes filling of contact holes difficult.

SUMMARY OF THE INVENTION

[0005] In accordance with an aspect of the present invention, afabrication process forms an interface control layer before a blanketdeposit of a conductive layer of aluminum or a similar material. Theinterface control layer is a thin layer typically including multipleatomic layers. The interface control layer provides uniformly anddensely distributed nucleation sites from which the conductive layergrows uniformly. Accordingly, the fabrication process forms asmooth-surfaced aluminum layer that can fill fine contact holes.

[0006] In accordance with one embodiment of the present invention, asemiconductor device includes an interlayer dielectric (ILD) film havinga contact hole on a semiconductor substrate. The contact hole exposes aconductive region of the semiconductor substrate. The fabrication methodforms an interface control layer having multiple atomic layers depositedon an inner wall of the contact hole and an upper surface of theinterlayer dielectric film and then deposits Al on the interface controllayer by a chemical vapor deposition (CVD) to form both a contact plugin the contact hole and an interconnection layer connected to thecontact plug. Between forming the interface control layer but afterforming the ILD film, an ohmic layer can be formed on the exposedconductive region of the semiconductor substrate, the side wall of thecontact hole in the interlayer dielectric film, and the upper surface ofthe interlayer dielectric film; and a barrier layer such as a Ti-richTiN layer can be formed on the ohmic layer.

[0007] An atomic layer deposition (ALD), cyclic CVD or digital CVD canform the interface control layer by depositing a single metal or analloy film. For example, the interface control layer can be a thinaluminum (Al) film containing silicon (Si). To form such interfacecontrol layer, a flow of Si-containing gas is applied a structureincluding the barrier layer, to adsorb Si to the surface of the barrierlayer, and then excess Si-containing gas is removed from around thestructure. Applying an Al-containing gas to the resultant structureadsorbs Al to the surface of the barrier layer and to the adsorbed Si.Then, excess Al-containing gas is removed from around the structure, andthese steps are repeated to form on the barrier layer a thin Al filmcontaining Si. During the Al adsorption, hydrogen (H₂) gas may besupplied together with the Al-containing gas to facilitate deposition ofAl.

[0008] Forming the contact plug and the interconnection layer can beperformed in-situ, in the same processing device or chamber in which theinterface control layer is formed.

[0009] The fabrication method can further include adsorbing hydrogen ornitrogen to the surface of the interface control layer to form a surfacetreatment layer on the interface control layer, before forming thecontact plug and the interconnection layer. The surface treatment layerprevents oxidation of the interface control layer and maintains thedesired density and uniformity of nucleation sites.

[0010] In addition to the above steps, fabrication methods in accordancewith other embodiments of the invention can include annealing afterdepositing the Al interconnection layer on the interface control layer.The annealing forms an interconnection layer doped by a diffusion ofatoms from the interface control layer into the interconnection layer.In the method, the interface control layer is typically copper (Cu),titanium (Ti), tungsten (W), silicon (Si), tantalum (Ta) or silver (Ag).

[0011] When the interface control layer contains copper, a source gassuch as (hexafluoroacetyl)copper(trimethylvinylsilane) [(hfac)Cu(TMVS)],CuCl₂, Cu₂I₄, or a combination thereof is applied to adsorb Cu to thesurface of the barrier layer. To form multiple atomic layers, thechamber containing the resultant structure is purged using a purginggas, and then applying the copper containing gas and purging arerepeated. Annealing for diffusion of copper is typically performed at300 to 650° C.

[0012] When the interface control layer is formed of Ti, a gas such asTiCl₄, tridiethylamine titanate (TDEAT), tridimethylamine titanate(TDMAT), or a combination thereof is flushed across the surface toadsorb Ti.

[0013] When the interface control layer is formed of W, the flushing isperformed with WF₆ gas.

[0014] When the interface control layer is formed of Si, a gas such asSiH₄, SiH₃Cl, SiHCl₃, Si₂H₆, SiCl₄ or a combination thereof is flushed.Here, annealing may be performed at 400 to 650° C.

[0015] Another method for fabricating a semiconductor device includesforming an interlayer dielectric (ILD) film having a contact hole thatexposes a conductive region of a semiconductor substrate. A firstinterface control layer as a thin Al film containing Si is formed on theinner wall of the contact hole and the upper surface of the interlayerdielectric film, to a thickness on the order of several angstroms toseveral tens of angstroms. Then, a second interface control layer havinga plurality of atomic layers of a material such as Cu is formed on thefirst interface control layer, and an Al blanket deposition is performedon the resultant structure by chemical vapor deposition (CVD), to form aconductive layer filling the contact hole and simultaneously coveringthe upper surface of the interlayer dielectric film. Annealing theresultant structure forms an Al interconnection layer doped with Si andCu.

[0016] Between forming the first interface control layer and forming theILD film, an ohmic layer can be formed on the exposed conductive regionof the substrate, the side wall of the interlayer dielectric film in thecontact hole, and the upper surface of the interlayer dielectric film,and then a barrier layer is formed on the ohmic layer. The firstinterface control layer is formed on the barrier layer.

[0017] Atomic layer deposition (ALD), cyclic CVD or digital CVD can formthe first and second interface control layers, and the first interfacecontrol layer, the second interface control layer and the conductivelayer can be formed successively formed in-situ in the same depositionchamber. In one embodiment, between forming the conductive layer andforming the second interface control layer, a surface treatment layer onthe second interface control layer is formed to prevent oxidation of thesurface of the second interface control layer.

[0018] According to an aspect of the present invention, a semiconductordevice fabrication method forms an Al interconnection layer havingexcellent surface morphology and thereby improves reliability of theinterconnection layer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The features and advantages of the present invention will becomemore apparent by describing in detail specific embodiments thereof withreference to the attached drawings in which:

[0020]FIGS. 1A through 1E are sectional views of semiconductorstructures illustrating a semiconductor device fabrication methodaccording to an embodiment of the present invention;

[0021]FIGS. 2A through 2D are sectional views of semiconductorstructures illustrating a semiconductor device fabrication methodaccording to another embodiment of the present invention; and

[0022]FIGS. 3A through 3E are sectional views of semiconductorstructures illustrating a semiconductor device fabrication methodaccording to still another embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023]FIGS. 1A to 1E illustrate structures formed during a semiconductordevice fabrication method according to an embodiment of the presentinvention. FIG. 1A shows an interlayer dielectric (ILD) film 20 on asemiconductor substrate 10. ILD film 20 includes a contact hole H1 thatexposes conductive region 12 of semiconductor substrate. ILD film 20 canbe any type of dielectric of insulating layer that separates conductivelayers in a semiconductor device. In an exemplary embodiment, ILD film20 is an oxide layer, and known oxide deposition and patterning of thedeposited oxide layer form ILD film 20.

[0024] Referring to FIG. 1B, conventional chemical or physical vapordeposition processes form an ohmic layer 32, e.g., Ti layer, on innerwalls of contact hole H1 and on a top surface of ILD film 20, and abarrier layer 34 on ohmic layer 32. In the exemplary embodiment, barrierlayer 34 is a Ti-rich TiN layer containing a higher Ti content than aregular TiN layer. A conventional CVD or PVD process can form theTi-rich TiN barrier layer. In the conventional CVD process, the rationof NH₃ to TiCl₄ can be decreased in order to increase the amount ofTiCl₄ used and increase the amount of Ti in the deposited layer. In thePVD process, the reactive gas ratio of N₂ to Ar can be decreased toincrease the amount of Ar relative to the amount of N₂.

[0025] Referring to FIG. 1 C, an atomic layer deposition (ALD), a cyclicchemical vapor deposition, or a digital chemical vapor deposition formsan interface control layer 42. Atomic layer deposition, cyclic chemicalvapor deposition, or digital chemical vapor deposition are processeswell know in the art and can be performed in the conventional manner toform thin layers. In the exemplary embodiment, interface control layer42 is an aluminum (Al) film containing silicon (Si) and includesmultiple atomic layers. Interface control layer 42 is on the inner wallof contact hole H1 and the upper surface of ILD film 20 which have beencovered with ohmic layer 32 and barrier layer 34. Interface controllayer 42 has a thickness of several angstroms to several tens ofangstroms, e.g., 3 to 50 Å, and preferably, less than 10 Å.

[0026] An advantage of ALD in forming interface control layer 42 is thatALD can form highly densified thin layers by supplying required sourcegases in sequence. Thus, when CVD forms an Al layer several thousands ofangstroms thick on interface control layer 42, the Al layer can have asmooth flat surface morphology and completely fill contact hole H1,which has a large step difference and a high aspect ratio.

[0027] In the exemplary embodiment, ALD that forms interface controllayer 42 supplies a flow of Si-containing gas, such as silane (SiH₄), atabout 100 sccm (standard cubic centimeter per minute) for about 30seconds or less in a carrier gas such as H₂, Ar, or He at about 100sccm, and the semiconductor structure including barrier layer 34 is inan ALD chamber at 300 to 800° C., preferably about 320 to 420° C. and apressure of about 0.1 to 5 torr, preferably 0.5 to 1.5 torr. Under theseconditions, SiH₄ decomposes so that Si atoms are adsorbed to barrierlayer 34. SiH₃Cl, SiH₂Cl₂, SiHCl₃, Si₂H₆ or SiCl₄ also can be used asthe Si-containing gas. Excess Ti in Ti-rich TiN barrier layer 34 reactswith Si from SiH₄ to improve adsorption of Si to barrier layer 34.

[0028] After the Si adsorption, excess SiH₄ is removed from around thestructure by purging or pumping out the chamber containing thestructure. Then, a flow of an Al-containing gas, such as trimethylaluminum (TMA), is supplied to barrier layer 34 to which Si atoms havebeen adsorbed. As a result, the methyl group of the TMA vaporizesthrough a reaction 1 between TMA and SiH₄ on the surface of barrierlayer so that Al atoms are adsorbed to barrier layer 34.

Al(CH₃)₃+SiH₄→Si—Al+CH₄(↑)  Reaction 1

[0029] To promote the Al adsorption, H₂ gas is provided together withthe TMA, so that a reaction 2 also occurs.

Al(CH₃)₃+H₂→Al+CH₄(↑)  Reaction 2

[0030] In the exemplary embodiment, the flow rate of the Al-containinggas is 10 sccm or less, preferably 2 to 3 sccm for between about 0.1seconds and about 300 seconds, in a carrier gas of (H₂, Ar, or He) witha flow between 0 and 500 sccm, preferably about 80 to 120 sccm. Thepressure in the chamber is between about 0.1 and 5 torr, preferablybetween 0.5 and 1.5 torr, and the temperature in the chamber remainsbetween about 320 and 420° C. Dimethylamluminum hydride (DMAH),dimethylethylamine alane (DMEAA) or triisobutylaluminum (TIBA) also canbe used as the Al-containing gas. After the Al adsorption (ordeposition) is completed, excess TMA is purged from the chambercontaining the semiconductor structure.

[0031] The above-described Si and Al adsorption processes are repeatedas many times as required to form interface control layer 42 having adesirable thickness, for example between 3 and 10 Å. The deposition rateof interface control layer 42 is controlled to produce a highlydensified Al layer containing Si, which has a uniform grain size. Then,when CVD forms an Al interconnection layer on interface control layer42, the Al interconnection layer grows uniformly from uniformly anddensely distributed nucleation sites. The Si atoms in interface controllayer 42 precipitate along Al grain boundaries and within grains,thereby promoting uniform distribution of Al nucleation sites andpreventing Al agglomeration. Otherwise, Al easily agglomerates, and theAl layer grows rapidly at specific nucleation sites as a thickness ofthe Al interconnection layer increases. Thus, it is important to controla deposition rate of interface control layer 42 to ensure grainexcellent crystallization characteristics and a high density of closenucleation sites.

[0032] ALD forms interface control layer 42 in the above embodiment.Alternatively, cyclic CVD or digital CVD can form the interface controllayer 42. Interface control layer 42 is formed in units of atomic layersin which uniform grains are densely formed. Accordingly, makinginterface control layer 42, which has a number of dense and uniformatomic layers, requires a comparatively low deposition rate, so thatuniform Al nuclei are randomly distributed on barrier layer 34.Typically, the deposition rate of a Al interconnection layer is higherthan that of interface control layer 42, but the Al interconnectionlayer still forms with a uniform surface morphology.

[0033] Referring to FIG. 1D, a hydrogen-containing gas such as hydrogen(H₂) or silane (SiH₄) or nitrogen-containing gas such as ammonia NH₃ issupplied to the surface of interface control layer 42, so that hydrogenor nitrogen is adsorbed to interface control layer 42 and forms a thinsurface treatment layer 44 on interface control layer 42. In theexemplary embodiment, the reaction chamber containing the semiconductorstructure including interface control layer 42 is filled with hydrogenor ammonia at a pressure between about 0.1 and 50 torr, preferably about1 torr, at a temperature between about 200 and 500° C., preferablybetween about 380 and 420° C. The gas flow rate is between about 50 and500 sccm, preferably about 100 sccm, for a period between about 30seconds and 30 minutes, preferably about 1 minute. Surface treatmentlayer 44 helps prevent oxidation of interface control layer 42 if thesemiconductor structure is exposed to air before formation of theinterconnection layer, for example, when moving the semiconductorstructure to another processing apparatus for formation of aninterconnection layer. However, forming treatment layer 44 can beomitted when the interconnection layer can be in-situ after forminginterface control layer 42.

[0034] Referring to FIG. 1E, a CVD blanket deposition of Al forms acontact plug 52 in contact hole H1 and a 1,000 to 8,000 Å thickinterconnection layer 50 connected to contact plug 52 on surfacetreatment layer 44. In the exemplary embodiment, CVD forming plug 52 andlayer 50 uses a flow between 1 and 50 sccm, preferably between 3 and 5sccm, of TMA in a carrier gas flow between about 10 and 500 sccm,preferably between 90 and 110 sccm, through a chamber at a temperaturebetween about 100 and 500° C., preferably between 110 and 130° C. and apressure between about 0.1 and 100 torr, preferably between about 0.5and 1.5 torr. Here, because interface control layer 42 is previouslyformed in contact hole H1, contact plug 52 can completely fill contacthole H1 and simultaneously interconnection layer 50 having the excellentsurface morphology can be obtained.

[0035]FIGS. 2A to 2D illustrate a method for fabricating a semiconductordevice according to another embodiment of the present invention.

[0036] Referring to FIG. 2A, in the same way as described with referenceto FIGS. 1A and 1B, an ILD film 120 having a contact hole H2 is formedon a semiconductor substrate 110; an ohmic layer 132 is formed on innerwalls of contact hole H2 and an upper surface of ILD film 120; and a TiNbarrier layer 134 is formed on ohmic layer 132.

[0037] Then, ALD forms an interface control layer 142, which is made ofcopper (Cu), titanium (Ti), tungsten (W), silicon (Si), tantalum (Ta) orsilver (Ag), on the inner wall of contact hole H2 and the surface of ILDfilm 120 which have been covered with ohmic layer 132 and barrier layer134. Interface control layer 142 contains multiple atomic layers and hasa thickness of several angstroms to several tens of angstroms,preferably, less than 20 Å.

[0038] In an exemplary embodiment described further below, interfacecontrol layer 142 is Cu. In an ALD for forming Cu interface controllayer, (hexafluoroacetyl) copper (trimethylvinylsilane)[(hfac)Cu(TMVS)], CuCl₂, Cu₂I₄ or a combination thereof, as a source gasof Cu, is flushed on barrier layer 134, so that Cu atoms are adsorbed tobarrier layer 134. The exemplary ALD process use a flow of(hfac)Cu(TMVS) at a flow rate between 1 sccm and 500 sccm, preferably 10sccm, at a temperature between about 100 and 400° C., preferably about220 to 270° C., and a pressure between about 0.1 and 100 torr,preferably between about 0.5 and 1.5 torr, for between 1 second and 10minutes, preferably about 1 minute. Then, excess source gas is purgedfrom around the semiconductor structure using hydrogen (H₂), helium (He)or argon (Ar) gas. The flushing and purging are repeated as many timesas required to form interface control layer 142 formed of multiple thinCu atomic layers deposited in sequence.

[0039] When interface control layer 142 is Ti, TiCl₄, tridiethylaminetitanate (TDEAT), tridimethylamine titanate (TDMAT) gas or a combinationthereof is used as a source gas. When interface control layer 142 is W,WF₆ gas is used; and for a Si interface control layer, SiH₃Cl, SiH₂Cl₂,SiHCl₃, Si₂H₆, SiCl₄ gas or a combination thereof is used. Processparameters for the ALD process vary according to the source gas.

[0040] Referring to FIG. 2B, a flow of a hydrogen-containing ornitrogen-containing gas is supplied to the surface of interface controllayer 142, so that hydrogen or nitrogen is adsorbed to interface controllayer 142 and forms a thin surface treatment layer 144 on interfacecontrol layer 142. Surface treatment layer 144 helps prevent oxidationof interface control layer 142.

[0041] Referring to FIG. 2C, a CVD blanket deposition of Al fillscontact hole H2 and forms conductive layer 150 on surface treatmentlayer 144. When the CVD blanket deposition is performed in-situ afterforming interface control layer 142, forming surface treatment layer 144may be omitted.

[0042] Referring to FIG. 2C, Al blanket deposition on the semiconductorstructure fills the contact hole H2 and simultaneously forms aconductive layer 150 covering the upper surface of ILD film 120. In theexemplary embodiment, Cu interface control layer 142 promotes uniform Algrain nucleation and prevents Al agglomeration in the CVD blanketdeposition. Accordingly, interconnection layer 150 has excellent surfacemorphology even if interconnection layer 150 is thick. Preferably,forming conductive layer 150 is in-situ after forming interface controllayer 142.

[0043] Referring to FIG. 2D, annealing form an Al interconnection layer150 a doped with Cu by promoting a diffusion of Cu atoms from interfacecontrol layer 142 into conductive layer 150. The annealing is performedat 300 to 650° C., preferably 450 to 500° C., for between 5 minutes and60 minutes, preferably about 30 minutes. For example, when 0.5 atomic %Cu doping in Al interconnection layer 150 a is required, Cu interfacecontrol layer 142 is to be about 20 Å thick. The doping of Alinterconnection layer 150 a improves reliability of Al interconnectionlayer 150 a.

[0044] As described above, when CVD forms conductive layer 150 while Cuof interface control layer 142 is adsorbed to the TiN surface of barrierlayer 134, an Al conductive layer having excellent surface morphologycan be obtained even if the Al conductive layer is thick. Also, Cu inthe Al interconnection layer 150 a acts as a dopant, thereby improvingreliability of the interconnection layer. An interface control layerformed of Ti, W, Si, Ta or Ag can produce the same effect as a Cuinterface control layer. However, required annealing temperature varydepending on the composition of interface control layer. For example, aTi interface control layer's annealing temperature is about 400 to 650°C.

[0045]FIGS. 3A through 3E illustrate a fabrication method to stillanother embodiment of the present invention. Referring to FIG. 3A, anILD film 220 is formed on a semiconductor substrate 210 with a contacthole H3 through ILD 220 exposing a conductive region of semiconductorsubstrate 210. An ohmic layer 232 is formed of Ti on the exposedconductive region of semiconductor substrate 210, the side walls ofcontact hole H3 in ILD film 220, and the upper surface of ILD film 220,and then a barrier layer 234 is formed of TiN on ohmic layer 232. Theselayers can be formed in sequence by the same processes described abovein reference to corresponding layers illustrated in FIGS. 1A and 1B.

[0046] Then, a first interface control layer 242, as a thin Al filmcontaining Si, is formed on barrier layer 234, to a thickness on theorder of several angstroms to several tens of angstroms, preferably,less than 10 Å. Again, the same method described with reference to FIG.1C for forming interface control layer 42 can form first interfacecontrol layer 242.

[0047] Referring to FIG. 3B, a second interface control layer 244, whichis formed of Cu, is formed on first interface control layer 242 by thesame method as described with reference to FIG. 2A. Alternatively,second interface control layer 244 may also be formed of Ti, W, Si, Taor Ag, instead of Cu. In this embodiment, second interface control layer244 is continuous thin layers as described above. However, secondinterface control layer 244 may include multiple separated islands onfirst interface control layer 242. Such islands can be formed by using amask to limit formation of second interface control layer 244 tospecific areas. Alternatively, selective etching can pattern acontinuous layer.

[0048] Referring to FIG. 3C, a hydrogen-containing gas ornitrogen-containing gas is supplied to the surface of interface controllayer 244 to form a thin surface treatment layer 246 on interfacecontrol layer 244 in the same way that was described with reference toFIGS. 1D and 2B. Surface treatment layer 246 helps prevent oxidation ofinterface control layer 244, for example, when moving the semiconductorstructure to another processing apparatus.

[0049] Referring to FIG. 3D, a CVD blanket deposition of Al fillscontact hole H3 and forms conductive layer 250 on surface treatmentlayer 246. When the CVD blanket deposition is performed in-situ afterforming interface control layer 244, forming surface treatment layer 246may be omitted. Like the previously described methods, interface controllayers 242 and 244 promote uniform Al grain nucleation and prevents Alagglomeration in the CVD blanket deposition, so that conductive layer250 can have a uniform surface morphology.

[0050] Referring to FIG. 3E, an annealing of conductive layer 250 formsan Al interconnection layer 250 a doped with Cu by promoting a diffusionof Cu atoms from second interface control layer 244 into conductivelayer 250. The annealing is performed at about 300 to 500° C.,preferably, about 450 to 480° C. The doping of Al interconnection layer250 a improves reliability of Al interconnection layer 250 a.

[0051] As described above, an interface control layer formed accordingto the present invention promotes a uniform deposition of aninterconnection layer which is formed on the interface control layer, sothat the interconnection layer can have a uniform surface morphology. Inaddition, the interface control layer can act as a s dopant of theinterconnection layer, thereby improving reliability of theinterconnection layer.

[0052] Although the invention has been described with reference toparticular embodiments, the description is only an example of theinventor's application and should not be taken as a limitation. Variousadaptations and combinations of features of the embodiments disclosedare within the scope of the invention as defined by the followingclaims.

What is claimed is:
 1. A semiconductor device fabrication methodcomprising: (a) forming an interlayer dielectric (ILD) film having acontact hole, the contact hole exposing a conductive region of anunderlying structure; (b) forming an interface control layer of aplurality of atomic layers continuously deposited on inner walls of thecontact hole and an upper surface of the interlayer dielectric film; and(c) forming a contact plug in the contact hole and an interconnectionlayer on the interface control layer by depositing aluminum in thecontact hole and on the interface control layer.
 2. The method of claim1 , wherein after step (a) and before step (b), the method furthercomprises: forming an ohmic layer on the inner walls of the contact holeand on the upper surface of the interlayer dielectric film; and forminga barrier layer on the ohmic layer, wherein the interface control layeris formed on the barrier layer.
 3. The method of claim 2 , wherein theinterface control layer is an aluminum (Al) layer containing silicon(Si).
 4. The method of claim 3 , wherein atomic layer deposition (ALD)forms the interface control layer.
 5. The method of claim 4 , whereinstep (b) comprises: (b1) flowing a Si-containing gas on the barrierlayer, so that Si atoms are adsorbed to the barrier layer; (b2) removingexcess Si-containing gas from around the barrier layer; (b3) flowing anAl-containing gas on the barrier layer to which the Si atoms wereadsorbed, so that Al atoms are adsorbed to the barrier layer; (b4)removing excess Al-containing gas from around the barrier layer; and(b5) repeating steps (b1) through (b4) to form the Al layer containingSi on the barrier layer.
 6. The method of claim 5 , wherein the barrierlayer is a titanium (Ti)-rich titanium nitride (TiN) layer.
 7. Themethod of claim 5 , wherein hydrogen (H₂) gas is supplied together withthe Al-containing gas in step (b3) to facilitate deposition of Al atoms.8. The method of claim 1 , further comprising annealing thesemiconductor device after step (c), so that the interconnection layeris doped with metal atoms from the interface control layer.
 9. Themethod of claim 8 , wherein after step (a) and before step (b), themethod further comprises: forming an ohmic layer on the inner walls ofthe contact hole and on the upper surface of the interlayer dielectricfilm; and forming a barrier layer on the ohmic layer, wherein theinterface control layer is formed on the barrier layer in step (b). 10.The method of claim 9 , wherein the interface control layer is formed ofa material selected from a group consisting of copper (Cu), titanium(Ti), tungsten (W), silicon (Si), tantalum (Ta), and silver (Ag). 11.The method of claim 10 , wherein a method selected from a groupconsisting of atomic layer deposition (ALD), cyclic CVD, and digital CVDforms the interface control layer.
 12. The method of claim 10 , whereinthe interface control layer is formed of Cu, and step (b) comprises:(b1) flowing a source gas selected from a group consisting of(hexafluoroacetyl)copper(trimethylvinylsilane), CuCl₂, Cu₂I₄, andcombinations thereof so that Cu atoms are adsorbed to the barrier layer;(b2) purging the source gas from around the semiconductor device afterstep (b1); and (b3) repeating steps (b1) and (b2).
 13. The method ofclaim 11 , wherein the interface control layer is formed of Ti, and step(b) comprises flowing a gas selected from a group consisting of TiCl₄,tridiethylamine titanate, tridimethylamine titanate, and combinationsthereof.
 14. The method of claim 11 , wherein the interface controllayer is formed of W, and step (b) comprises flowing WF₆ gas.
 15. Themethod of claim 11 , wherein the interface control layer is formed ofSi, and step (b) comprises flowing a gas selected from a groupconsisting of SiH₃Cl, SiH₂Cl₂, SiHCl₃, Si₂H₆ or SiCl₄ and combinationsthereof.
 16. The method claim 1 , further comprising annealing thesemiconductor device after step (c) so that the interconnection layer isdoped with metal atoms from the interface control layer, and step (b)comprises: (b′) forming a first interface control layer as an Al filmcontaining Si and a plurality of atomic layers on the inner wall of thecontact hole and the upper surface of the interlayer dielectric film;and (b″) forming a second interface control layer having a plurality ofatomic layers continuously deposited on the first interface controllayer.
 17. The method of claim 16 , wherein after step (a) and beforestep (b), the method further comprises: forming an ohmic layer on theinner walls of the contact hole and on the upper surface of theinterlayer dielectric film; and forming a barrier layer on the ohmiclayer, wherein the first interface control layer is formed on thebarrier layer.
 18. The method of claim 17 , wherein atomic layerdeposition (ALD) forms the first and second interface control layers.19. The method of claim 18 , wherein step (b′) comprises: (b′1) applyinga Si-containing gas to the barrier layer so that Si atoms are adsorbedto the barrier layer; (b′2) removing excess Si-containing gas fromaround the semiconductor device; (b′3) applying an Al-containing gas tothe barrier layer to which the Si atoms are adsorbed, so that Al atomsare adsorbed to the barrier layer; (b′4) removing excess Al-containinggas from around the semiconductor device; and (b′5) repeating steps(b′1) through (b′4) to form the Al film containing Si on the barrierlayer.
 20. The method of claim 19 , wherein hydrogen (H₂) gas is appliedtogether with the Al-containing gas in step (b′3).
 21. The method ofclaim 18 , wherein the second interface control layer is formed of amaterial selected from a group consisting of copper (Cu), titanium (Ti),tungsten (W), silicon (Si), tantalum (Ta) and silver (Ag).
 22. Themethod of claim 21 , wherein the second interface control layer isformed of Cu, and step (b″) comprises: (b″1) applying a gas selectedfrom a group consisting of(hexafluoroacetyl)copper(trimethylvinylsilane) ) [(hfac)Cu(TMVS)],CuCl₂, Cu₂l₄, and combinations thereof so that Cu atoms are adsorbed tothe barrier layer; (b″2) purging from around the semiconductor deviceafter step (b″11); and (b″3) repeating s steps (b″1) an d (b″2).
 23. Themethod of claim 1 , wherein step (c) is performed in-situ after step(b).
 24. The method of claim 1 , wherein after step (b) and before step(c), the method further comprises forming a surface treatment layer onthe interface control layer, the surface treatment layer preventingoxidation of the surface of the interface control layer, wherein Aldeposition in step (c) is performed on the surface treatment layer. 25.The method of claim 24 , wherein the surface treatment layer is formedby adsorbing hydrogen or nitrogen to the interface control layer.